Branion® Ionomer Resin is a solution-processable anion-exchange ionomer designed for catalyst inks and electrochemical electrode applications. 

Branion® Ionomer Resin offers an ion exchange capacity (IEC) of 2.7–2.9 meq/g and can be converted from its halide form to the hydroxide (OH⁻) form following catalyst ink deposition. Its combination of ionic conductivity and water uptake makes it suitable for research and development of anion-exchange membrane electrochemical systems, including AEM water electrolysis and related alkaline electrochemical applications.

Key Features

• Anion-exchange ionomer resin for catalyst ink and electrode applications
• Solution-processable for convenient catalyst ink formulation
• Recommended solution concentration: 5 wt%
• IEC: 2.7–2.9 meq/g
• Conductivity: 20–40 mS/cm at 20 °C (Cl⁻/HCO₃⁻ form)
• Water uptake: 60–80% at 20 °C (OH⁻ form)
• Can be converted to the OH⁻ form using 1 M KOH
• Compatible with DMSO-based solution processing

Solution Preparation

For a 5 wt% solution, dissolve 1 g of Branion® Ionomer Resin in 19 g of DMSO. Heat the solution to approximately 50 °C in a closed container overnight. Vacuum filtering through 2–4 μm filter paper may be used to further improve solution purity.

Following deposition of the ionomer-catalyst ink onto a membrane or electrode, the ionomer can be converted from the halide form to the OH⁻ form by soaking in 1 M KOH.

Storage

Store Branion® Ionomer Resin in a cool, dry location with minimal exposure to light.